Exactly how much is he getting paid in order to even agree to a penalty like that?

The guy who built the Hoover Dam had, for back then, a healthy bonus clause if he finished early and he did. In today's dollars, he pocketed several million -- but he treated his depression era workers like shiat, managed to get a bunch killed, there were no safety regulations and he had them living in tents in the dessert heat while he postponed building their promised camp for as long as possible.

(Today, he's lauded as a hero.)

I wonder if the contractor for this job has an early completion bonus? If so, it must be pretty big for him to even take the job with such a penalty clause.